This three year project will focus on an important issue affecting the delivery of substance abuse services across the nation: the implementation of managed care funding mechanisms on the service relationships involving outpatient substance abuse services. Some recent findings suggest that the introduction of managed care funding practices decreases the number and/or intensity of relationships among providers of care for persons with mental health and substance abuse disorders. Many of these studies however involve intra rather than interorganizational relationships, of which we know little. Findings also show that substance abuse services are most effective for persons with both mental health and substance abuse disorders if they receive services for both disorders concomitantly and receive an appropriate number of them. Managed care, with its practices of decreasing service use and defining provider networks, may have the consequence of disrupting the local service system of care. This study is focused on understanding which service relationships are implicated by the introduction or the intensification of managed care payment practices for providers serving persons with substance abuse and mental health disorders. This study will use in-person surveys to collect data from approximately 420 service providers in 60 sites across the US. In each of 60 sites at least one outpatient substance abuse organization, determined from a different study currently underway, is identified along with an appropriate respondent. This person is asked to identify up to six other local providers of care of mental health, vocational, and primary health care in their organization's service network for persons with substance abuse disorders along with attributes of their organization or service program. In addition, these other identified organizations are also interviewed and asked a similar set of questions. Interorganizational network methods and dyadic analysis of the relationships over time between these substance abuse providers and other local providers of supportive care will be used to determine the impact of managed care on these service linkages controlling for important environmental, organizational, or contextual factors. The project will use a longitudinal data design to build appropriate relational models. Findings will be related and communicated to program managers and directors who are engaged in providing appropriate and responsive care to this vulnerable population.